Question: The fifth term of an arithmetic sequence is $11$. If the difference between two consecutive terms is $1$, what is the product of the first two terms?
Solution: Simply back up from $11$. Since $11$ is the fifth term, the first term will be $11 - 4 \cdot 1 = 7$, and the second term will be $11 - 3\cdot 1 = 8$. So the answer is $7 \cdot 8 = \boxed{56}$.